SIGNIFICANT ACCOUNTING POLICIES AND NEW ACCOUNTING PRONOUNCEMENTS (Details) (USD $)	12 Months Ended
	Jan. 01, 2012 M segment D Y	Jan. 02, 2011	Jan. 03, 2010
Warranty period on power products sold (in years)	2
Revenue Recognition
Payment term, following shipment (in days)	30
Maximum percentage of dollar value of product to be exchanged (as a percent)	5.00%
Period of prior sales eligible for exchange (in months)	6
Period of price discount on purchase order (in years)	1
Cash and Cash Equivalents
Maximum original maturity to classify instruments as cash equivalents (in months)	3
Property and Equipment
Estimated useful lives of assets, minimum (in years)	3
Estimated useful lives of assets, maximum (in years)	30
Intangible Assets
Estimated useful lives of intangible assets, minimum (in months)	3
Estimated useful lives of intangible assets, maximum (in years)	20
Impairment of Long-Lived Assets and Goodwill
Goodwill impairment charge			$ 56,999,000	[1]
Restructuring Costs
Charges and expenses related to various restructuring efforts in connection with exit of factory		3,400,000	8,000,000
Income Taxes
Uncertain tax positions, threshold likelihood of realization for recognition (as a percent)	50.00%
Engineering and Research and Development
Research and development expenses	$ 30,200,000	$ 23,200,000	$ 15,600,000
Segment Reporting
Number of operating segments	2
Maximum
Warranty period on power products sold (in years)	10
Extended product warranty period (in years)	10
Minimum
Warranty period on power products sold (in years)	5
Extended product warranty period (in years)	5

[1] (d) As a result of the interim goodwill impairment test which utilized the discounted cash flow analysis and comparative market multiples to determine the Company's fair value for comparison to its carrying value, the Company recorded a goodwill impairment charge of $57.0 million in the consolidated statement of operations for the fiscal year ended January 3, 2010.